Western blot analysis to examine the levels of expression of various mutant derivatives of C5 protein in E.coli NHY322 cells. Lane M, magic markers/size standards (Invitrogen); lane 1, wild type C5 protein; lane 2, pBR322 (vector control); lane 3, C5 R46H/R62A; lane 4, C5 R46H/K66A; lane 5, C5 R46H/R67A; lane 6, C5 R46H/R70A; lane 7, C5 F18A/F22A; lane 8, C5 F22A/R62A; lane 9, C5 F22A/R67A; lane 10, C5 F18A/R62A; lane 11, C5 F18A/K66A; lane 12, C5 F18A/R67A; lane 13, C5 R62A/R67A; lane 14, C5 R62A/R70A; lane 15, C5 R67A/R70A; and lane 16, purified C5 protein (20 ng).